Bottom-Up Processing

The human brain is capable of perceiving and interpreting information or stimuli received through the sense organs (i.e., eyes, ears, nose, mouth, and skin) (Weiten, 1998). This ability to perceive and interpret stimulus allows the human being to make meaningful sense of the world and environment around them. However, even as the human being is able to perceive and interpret stimuli information through all sense organs, stimuli is most often or primarily interpreted using the visual (eyes) and auditory (ears) sense organs (Anderson, 2009). However, for the purpose of this paper, the visual information process will be examined.

The Stroop effect is demonstrated by the reaction time to determine a color when the color is printed in a different color’s name. Participants respond slower or make more errors when the meaning of the word is incongruent with the color of the word. Despite knowing the meaning of the word, participants showed incapability of ignoring the stimulus attribute. This reflects a clear instance of semantic interference and an unfathomed failure of selective attention (Stroop, 1935).

The Stroop (1935) effect is the inability to ignore a color word when the task is to report the ink color of that word (i.e., to say "green" to the word RED in green ink). The present study investigated whether object-based processing contributes to the Stroop effect. According to this view, observers are unable to ignore irrelevant features of an attended object (Kahneman & Henik, 1981). In three experiments, participants had to name the color of one of two superimposed rectangles and to ignore words that appeared in the relevant object, in the irrelevant object, or in the background. The words were congruent,

Attention is considered to be a core cognitive process, it refers to how people actively process specific information in the environment. Attention refers to how people select from information and stimuli in the environment, facilitating processing of some of the stimuli and inhibiting processing of others. "Everyone knows what attention is, it is the taking possession by the mind in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought...It implies withdrawal from some things in order to deal effectively with others, and is a condition which has a real opposite in the confused, dazed, scatterbrained state. “This definition of attention was proposed by psychologist William James (1890). This review will focus on literature that gives explanation to selective attention. Selective attention refers to the process where a person is able to select out of many stimuli and focus on the one they want and ignore other stimuli.

In the novel The Invisible Gorilla: How our Intuitions Deceive Us by Christopher Chabris and Daniel Simons, a deeper way of how the mind works is shown. The authors explain what they call the “illusion of attention” by providing experiments and illustrations. The message being passed is that we as humans might think we are always aware of our surroundings, but we actually miss what is right in front of us. People usually focus on one thing at a time, therefore the unexpected goes unnoticed. The book explains how the brain only focuses on the object or area you are concentrating on, making you “blind” to everything else. Many experiments were held to prove to the readers that our intuition deceives us.

It was found that tasks involving colors cause more interference. These two studies were similar to the present experiment, as they both required participants to verbally name colors while inhibiting themselves from naming the typed color, as fast as possible.

This study examined visual perception and the rates at which global and local features are reacted to with an aim of replicating and validating a previous experiment conducted by Navon (1977) to see if global processing was faster than local processing. There was 222 University of Newcastle students participating in the experiment, partaking in two phases, one centred round global processing, the other around local processing, where there reaction times were recorded using a computer program and imputed into a data worksheet. Results indicated that, as predicted, global processing occurred at a faster rate than local processing. It was concluded that global features were

This was achieved by presenting central cues, indicating the position of the target letter thus increasing focus. Through these experiments they found that when a subject is in a diffuse attention state (unfocussed) SOD do cause attentional capture and increase reaction time. However, if the subject was presented with a cue this same increase in reaction time was not observed. This led them to conclude that attentional capture from SOD is not automatic and instead propose a priority based visual attention system. In 2006 Neo and Chua conducted research which built upon Yantis and Jonides’ to further demonstrate effects of attentional capture on reaction time. They investigated whether sporadic use of the SOD increased the effect of attentional capture as well as investigated whether maintaining the same position for the target letter decreased reaction times. They found that SOD attentional capture did affect reaction times and unlike in Yantis and Jonides’ experiment they concluded SOD did trigger an automaticity response when used

This study examined whether participant’s response times to global target were faster than local targets. Participants had to identify global and local shapes and letters as quick as possible and the response times which were recorded to the computer data. The study was a replication of Navon’s (1977), (cited in Ness Smith and Thirkettle, 2014) experiment but differed, as it was a focused attention task whereas this experiment was a divided attention task. This was the same as Yovel (2001), (cited in Ness, Smith and Thirkettle, 2014) mixed attention task study which tested the global to local accounts. The current

Top-down processing as defined by the book is a stimulus processing that is determined by expectations, memory and knowledge rather than directly by the stimulus (Eysenck, 2012). A basic understanding of this is when I find myself waking-up in the middle of the night and feeling dehydrated so I will begin to make my way through my house to get water, but I will never turn on lights while making my way to the kitchen because in my mind I have a full understanding of how my house is laid-out allowing me to recall how to maneuver though my home without hitting anything. I think that top-down processing is the process of learning, and that as we create repetition and gain the ability to recall information with ease, and not requiring us to constantly think about each process of something. I use top-down process by just repeating things and I can use this with learning new things everyday by having a constant

The Speed of Processing theory, which is what tends to happen when a person processes an action without being aware of it, is one of them [5]. Naming the color of the font of a word is not as common as reading an actual word. What this means is that easy tasks that we tend to overlearn since childhood, such as reading every word we see, tend to go into effect in our brain right after visual contact. Another explanation lies in the Selective Attention theory. Broadbent's 1985 study can explain the Selective Attention theory. Broadbent declared that information first enters a "sensory buffer" [6]. After the information enters the sensory buffer, selection of one of the inputs takes place within the basis of its physical characteristics. Broadbent places emphasis on what he calls a "sensory buffer" or filter in his study. This filter is used to prevent the brain from processing excessive amounts of information that could cause it to become overwhelmed and lose its ability to process the data efficiently [6]. The data that does not go through the filter does not become processed and eventually disintegrates [6]. Reading words does not require as much attention as naming the font color of a word does, which is why selective attention takes place [6]. Overall, the mind chooses to work with the task that requires the least amount of

Early studies have widely researched attention with selective processing (Driver, 2001). Broadbent (1958) filter theory of attention states that certain information does not require focal attention. It is based on certain stimulus attributes such as colour and shape (Friedenberg, 2012). A previous study carried out by Treisman and Schmidt (1982) proposes that when attention is diverted from a display of several figures, the participants incorrectly combine the features of colour and shape therefore increases the illusory conjunctions portrayed by the participants (Tsal, 1989). Another study by Shaw (1978) found that reaction time of participant to identify targets varied with the probability that a target would appear in a particular display location. These results indicate that different amounts of attention towards the targets are distributed to different positions in the visual field. However, Houck and Hoffman (1986) found that the feature integration of colour and orientation can sometimes be accomplished without attention (James et al.,

The human brain has a limited capacity to deal with the incoming information but yet every moment we encounter a large variety of stimuli like sights, sounds and smells. However, as mentioned above if we encounter stimuli which conflict with our schemas, we reconstruct our memory in order to fit our schemas. The human brain therefore focuses on some aspects of the situation while ignoring the others in order to cope with the sensory barrage. This process of choosing stimuli is called selective attention. Eyewitnesses tend to collect information that relates to their interests and may ignore other vital aspects

The article by Avital-Cohen and Tsal (2016) discussed the flanker task experiment, which asserted that distractor interference happens unconsciously as a result of focused attention toward the target. The results from the original flanker task indicated that participants had slower responses for incongruent trials, since the distractors are inconsistent with the target and would require a different response (Avital-Cohen & Tsal, 2016). However, Avital-Cohen and Tsal (2016) questioned the findings from the flanker task experiment. They decided to challenge the idea that only the target stimuli receives top-down processing, and not the distractors (Avital-Cohen & Tsal, 2016). The first experiment aimed to test whether the distractor interference is purely bottom-up processing as claimed in the flanker task. The experiment manipulated participants’ expectations of the target using the context effect - a type of top-down processing - by changing the distractors to be either letters or digits (Psych 240 lecture, 9/21/16). Then, the researchers conducted a second experiment and eliminated the ambiguity of distractors. They wanted to test whether the result from experiment 1 was caused by an overall bias or the ambiguous distractors. In experiment 2, the researchers predicted that they would obtain similar results to the first experiment only if the results were due to an overall bias effect (Avital-Cohen & Tsal, 2016). This study allows us to deepen our understanding of available

Research carried out on attention has mainly been associated with the selective processing of incoming sensory information. It proposes, to some degree, our awareness of the world depends on what we choose to focus on and not simply the stimulation received by our senses. Attention is often linked to a filter that screens out most potential stimuli whilst allowing a select few to pass through into our conscious awareness, however, a great deal of debate has been devoted to where the filter is situated in the information processing chain (Martindale, 1991). Psychologists have made extensive contributions to this subject matter in the past century. Notable examples include Donald Broadbent's filter theory of attention (1958), which set the